Purpose: :
Recent studies in premature neonates have demonstrated the developmentof small retinal hemorrhages after the retinopathy of prematurityexam. The aim of this study is to investigate the intraocularpressures of premature infants at various points during theretinopathy of prematurity exam in order to understand the effectof the mechanical forces during the exam.

Methods: :
18 unique patients and 36 eyes were examined after informedconsent was obtained from the parental guardian. Intraocularpressures were measured after instillation of tetracaine witha Reichert ® tonopen prior to insertion of the speculum,after insertion of the speculum, during scleral depression,and after completion of scleral depression.

Results: :
36 eyes were included in the study. The average intraocularpressure of 30 eyes prior to insertion of the speculum was 35.9mm Hg (pressures could not be obtained in 6 eyes due to infantsize). The average intraocular pressure of the 36 eyes was 32.9mm Hg after insertion of the wire speculum. The average intraocularpressure of the 36 eyes was 77.7 mm Hg during scleral depression.The average intraocular pressure of the 36 eyes was 27.3 mmHg after completion of the examination with the speculum stillin place. No evidence of retinal hemorrhages were noted duringthe study.

Conclusions: :
Although no infants had evidence of retinal hemorrhages duringthe study, the intraocular pressures during the retinopathyof prematurity exam provided insight into the biomechanicaleffects of the exam. An interesting finding was the relativedecrease in intraocular pressure post scleral depression. Thismay indicate a possible compression-decompression mechanismcreated by exam. Additionally, the pressures greater than 70mm of Hg achieved during scleral depression would be enoughto impede perfusion of the central retinal artery. Thereforegreat care should be taken during the exam. This concept shouldbe considered during the use of cryotherapy as scleral depressionduring this procedure would likely elevate intraocular pressuresabove the perfusion pressures for a more extended period oftime than with laser therapy. Furthermore, it should be notedthat the measurement of intraocular pressures in infants maybe elevated simply because the infants are crying or agitated.However, further studies should be performed in older patientsto check intraocular pressures after the insertion of an eyespeculum. If the insertion of the speculum itself causes a changein intraocular pressure, great care should be used, especiallyin traumatic situations.